Portable telephone



FIG. 1 is a top, front and left side perspective view thereof, with the broken line matter being for illustrative purposes only and forming no part of the claimed design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a bottom plan view thereof;

FIG. 4 is a right side elevation view thereof; and,

FIG. 5 is a rear elevation view. 

The ornamental design for a portable telephone, as shown and described. 